<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
	   *{
        margin: 0;
        padding: 0;
	    }
		#root{
			width: 100%;
			height: 800px;
			margin: 0px auto;
			position: relative;/*子元素绝对定位于父元素，要求父元素*/

		}
		#header{
			height: 100px;
			background-color: #ccc;
		}
		#left{
			height: 76%;
			width: 20%;
			background-color: #ff0;
			position: absolute;
			top: 10%;
		

		}
		#middel{
			height: 76%;
			width: 40%;
			background-color: #f00;
			position: absolute;
			top: 10%;
			left: 20%;
			

		}
		#right{
			height: 76%;
			width: 40%;
			background-color: #f0f;
			position: absolute;
            top:10%;
			right: 0;
			
		}
		#foot{
			width: 100%;
			height: 14%;
	        background-color: #000;
	        position: absolute;
            bottom: 0;
		}
	</style>
</head>
<body> <!--CSS+Div布局-->
<div id="root">
	<div id="header"></div>
	<div id="left"></div>
	<div id="middel"></div>
	<div id="right"></div>
	<div id="foot"></div>
</div>
	
</body>
</html>